The subject matter disclosed herein relates to water heaters, and more particularly to apparatus and techniques for improving heat transfer between a condenser coil and a water storage tank of a heat pump water heater.
Condenser coils used in heat pump water heaters are made of metal tubing that must be bent into the intended shape. The process of bending the metal tubing typically results in a “spring back” from the intended shape, i.e., at least part of the metal tubing reverts back to its original shape or somewhere between its original shape and the intended shape. Thus, the accuracy of the condenser coil shape, as well as that of the coil size, may have great variation from the intended specifications.
In addition, the condenser coil is typically very flexible and may not be held tightly to the tank when installed on the tank. Water storage tank bottoms are generally not flat and thus, when the condenser coil is routed to the bottom of the tank, holding the condenser coil tightly to the bottom is difficult. The separation between the condenser coil and the bottom of the tank results in heat transfer inefficiencies, thus requiring greater energy use to heat the water in the storage tank to a desired temperature level.